Photographic shutter



Feb. 25,- 1964 F. SINGER 3,122,081

PHOT'OGRAPHIQ SHUTTER Filed Nov. 27, 1961 6 Sheets-Sheet 1 Feb. 25, 1964F. SINGER PHOTOGRAPHIC SHUTTER 6 Sheets-Sheet 2 Filed NOV. 27, 1961 Feb.25, 1964 F. SINGER PHOTOGRAPHIC SHUTTER 6 Sheets-Sheet 3 Filed Nov. 27.1961 Feb. 25, 1964 F. SINGER PHOTOGRAPHIC SHUTTER 6 Sheets-Sheet 4 FiledNov. 27, 1961 Feb. 25, 1964 F. SINGER 1 PHOTOGRAPHIC SHUTTER Filed Nov.27. 1961 6 Sheets-Sheet 5 v NM S R NN 8 3 mm mm 3 Feb. 25, 1964 F.SINGER 3,122,031

PHOTOGRAPHIC SHUTTER Filed Nov. 27, 1961 s Sheets-Sheet s tion.

United States Patent This invention relates to a photographic shutter,more particularly a shutter of the type called an objective shutter or abetween-the-lens shutter, and especially but not exclusively to ashutter intended for use with a camera ,of the single lens reflex type,wherein the scene to be photographed is viewed by the photographerthrough'the same lens through which the pictureis taken and where,consequently, the shutter blades of the objective shutter must be openduring the viewfinding and focusing opera-' An object of the inventionis the provision of the generally improved and more satisfactoryphotographic shutter.

Another object is the provision of a shutter of the objective type,having simplified and more reliable mechanism for opening the shutterblades at the conclusion of the exposure (after first making provisionfor suitable protection of the photographic film from unwanted light) tomake the camera ready for viewing for the next exposure, -and simplifiedmechanism for closing the shutter blades at the end of the viewingoperation and prior to the actual making of the next exposure, sothatthe film blocking or protecting means can be moved to ineffectiveposition ready for the next exposure.

Another object of the invention is the provisionof a shutter so designedthat it eliminates the need for a rotatable ring on which the shutterblades are mounted, which ring is commonly used in prior shutters forsingle lens reflex cameras, in order to provide for opening the bladesfor viewing purposes.

Still another object is the provision of'irnproved means whereby theshutter blades are positively connected to the main shutter drivingmember or mastermember during the making of the actual'exposure, and arecompletely disconnected from and free of the master member at othertimes.

A further object is the provision of a photographic shutter of the kindabove mentioned, in combination with improved operating and controllingmechanism which may, if desired, be located partly within thephotographic camera itself. V

These and other desirable objects may be attained in the mannerdisclosed as an illustrative embodiment of the invention in thefollowing description and in the accon partying drawings forming a parthereof, in which:

FIG. 1 is a somewhat schematic front face View of a shutter according toa preferred embodiment of the invention, with parts removed in order toshow other parts beneath, the shutter being illustrated in the cocked ortensioned condition and with the shutter blades fully open for viewingthe scene to be photographed;

FIG. 2 is a similar View with the parts still in cooked or tensionedposition but with the exposure-making cycle in progress and with theshutter blades closed at the conclusion of the viewing operation andready to make the actual exposure, and with the master member stilllatched;

FIG. 3 is a similar view with the parts in position at an instant laterthan the position shown in FIG. 2, the master member now being unlatchedand ready to run down to make the actual exposure;

FIG. 4 is a similar view of the shutter in rest position at thecompletion of the exposure, the shutter blades 3,122,081 Patented Feb.25, 1964 again having opened for viewing after being closed at the endof the exposure;

H6. 5 is a section through a fragment of the shutter, takenapproximately on the line V-V of FIG. 1;

. FIG. 6 is a fragmentary schematic View of the camera body seen fromthe rear, with the rear wall and other parts removed in order to showinterior parts; and

FIG. 7 is a fragmentary schematic vertical section through the camerabody, taken approximately on the line VlI-VII of FF. 6. i Referringfirst to the construction of the shutter itself as shown in FIGS. l-5,the shutter parts are preferably mounted in the usual conventionalcasing of annular shape, having an outer cylincrical wall fragmentarilyshown at ll. 7 Within the shutter casing or housing is a base plate ormechanism plate 4 which lies close to the back wall of the shutterhousing and is in a general plane perpendicular to theoptical axis. Thismechanism plate 4 is held stationary within the shutter housing by anysuitable fastening means, such as screws. The front lens tube of theusual conventional construction is fastened to the base plate 4 by meansof screws passing through lugs or flanges 6 on the lens tube. The lenstube is fragmentarily shown at 3, and the space enclosed by it forms theoptical aperture 1d. The lens (not shown) is mounted, as usual, at leastpartly in the lens tube 8, with possibly other elements or components ofthe lens in a conventional rear lens tube. V

A driver ring or blade ring 12 for the shutter blades 14 is rotatableabout the optical axis (which axis passes centrally through the apertureid) in an annular recess formed between the base plate 4 and the frontlens tube 8, which members 4 and 8 are so shaped as to provide bearingsurfaces for holding the blade ring 12 against weak restoring spring,schematically shown at 13, tends to move the bla e ring 12 in acounterclockwise direction.

As customary, there are several shutter blades 14, usually about five,but the exact number thereof is unimportant for purposes of the presentinvention. Only one of the blades is illustrated, in order to simplifythe showing, all of them being of the same construction. Double endedblades (which may be described also as double wing or doublelobe blades)are used in the present shutter. Each blade is rotatably mounted on apivot 16 on the base plate 4, and each blade has a control slot 18extending in a radial direction with respect to its pivot 16. Controlpins 2h mounted in the blade ring 52 engage in these control slots, sothat rotation of the blade ring 12 about the optical axis results insimultaneous rotation of all of the shutter blades 14 on their pivot id,in the same direction or sense of rotation as that of the blade ring 12.

The master member mechanism or means for driving the blade ring to openand close the shutter blades for making the actual exposure (but not forother purposes such as viewing or focusing) will now be described.

The master member mechanism, considered as a whole,

includes the rotary driving element or master member 22 mountedforoscillation on a pivot 24 secured to the base plate 4. t A crank pin26 on the member 22 serves for pivotally mounting one end of anoscillatable coupling member 28. The other or free end of the couplingmember hasa notch or claw 30 for making coupling engagement with anoperating pin 31 on the blade ring 12.

pin 2% and the other end bearing against an edgeof the coupling element28. The driving force for turning the member 22 to open and close theshutter blades is sup plied by the main spring or master spring 36,wound around the pivot 24, one end of this main spring bearing against astationary pin fastened to the base plate 4, the other end of the springbeing bent and hooked into an opening 39 in the member 22.

The run down or rest position of the driving parts 22, 28 is shown inPEG. 4, while FIGS. 1, 2, and 3 show the tensioned or cocked position ofthese parts. For tensioning or cockin the master member, the followingmechanism is employed: the member 22 has a fowvardly bent or upstandinglug which lies in a recess in the gear wheel 42 mounted on the pivot 24,so that the gear wheel 42 and the driving member 22 are operativelyconnected non-rotatably to each other. The gear meshes with a secondgear wheel 44 which is fixed to a tensioning shaft was in non-rotatablemanner so that the shaft and the second gear wheel rotate with eachother. This shaft 4-6 is rotatable in the base plate 4 and extendsrearwardly through the base plate so as to be coupled to tcnsioningmeans I cated either in the rear part of the shutter housing or,preferably, in the body of the camera on which the shutter is mounted.At this point it may be desirable to mention that th word camera mayfrom time to time be used in two different senses, one being a broadsense including the shutter mechanism as part of the camera (this beingthe sense in which the word is commonly used by the public) and theother being the more restricted and technical sense of the word, meaningonly the camera body and the parts within it, as distinguished from theshutter mechanism and the shutter housing which protrudes from front ofthe camera body. The contexts will indicate in which sense the word isused in any particular instance.

For latching the driving element or master member in its tensioned orcocked position, there is a locking tooth member 48 mounted on the shaft45 and connected by a pin it? to the gear wheel so as to benon-rotatably fixed thereto. The latching tooth cooperates with alatching pawl 52 rotatable on a fixed pivot 54 fastened to the baseplate 4. A restoring spring so tends to turn the latch 52 in a clockwisedirection on its pivot 54-.

The arrangement which will now be described serves to prepare theshutter for an exposure, to unlatch the master member at the requiredtime for the actual exposure movement, and to open the shutter bladesagain at the completion of the exposure, ready for viewing and focusingof the next scene to be photographed. This mechanism comprises a controldisk 53 mounted on a control shaft 60 in non-rotatable relation thereto,so as to turn with the control snaft. This control shaft 66, like thetensioning shaft to, is rotatable in the base plate or mechanism plate 4and extends rearwardly through the base plate, the shafts il and beingparallel to each other and to the optical axis which passes through theexposure aperture 10. A spring 62 (FIGS. 6 and 7) located in the camerabody and operatively connected to the shaft es in the manner furtherdescribed below, serves at certain times to turn the shaft 6% in aclockwise di rection (when viewed from the front as in FIGS. 1-4 and arestoring spring 64 (FIG. 6) also located in the camera body tends toreturn the shaft 6% in a counterclockwise direction to its rest orrun-down position, all as will be further described below. The abovementioned control disk 53 has a forwardly bent or upstanding lug 66, andalso a pin 63 projecting from its front face, and it also has a tooth70.

The spring 62, when effective on the shaft so, tends to turn itclockwise with greater force than that exerted in the opposite directionby the spring By means of a device which will be described below inconnection with FIGS. 6 and 7, the spring 62 automatically becomesinoperative when the control disk 58 is in a ceratin angular position,so that the restoring spring 64 can act on the shaft oil to turn it in acounterclockwise direction and restore the shaft and the disk 53 totheir respective initial positions. During the reverse or restoringrotation of the control disk 5?: in the counterclockwise direction, thetooth '7@ on the disk engages behind a pin 72 on a blade opening lever7% which is mounted for rotation on the shaft on, and swings thisopening lever 74 in a counterclockwise direction so that the leverengages a driver pin 7'8 on the blade ring 12 and moves this blade ringin a clockwise direction to the interm diate position or centralposition shown in FIG. 1, in which position the shutter blades 14 areopen for viewing and focusing. A restoring spring 76, which is woundaround the control shaft 6%) and which has one end bearing against thehousing 2 and the other end bearing against the pin '72, urges theopening lever 74 in a clockwise direction.

Somewhat offset from the position of the shaft 60 is a three-armedclosing lever till rotatably mounted on a pivot 32 fixed in themechanism plate 4 and urged by a restoring spring 84, which is, forexample, wound around the pivot S2 and which has two arms embracingopposite sides of the pin 84a on the lever 30 and the stationary pin 85on the plate 4. Thus the restoring spring acts in both directions ofrotation, to hold the closing lever in the normal position shown inFIGS. 1, 3, and 4, while allowing it nevertheless to be displaced ineither direction from this normal position. In this normal position ofthe closing lever 89, one arm Silo thereof lies in the path of motion ofthe lug 66 on the control disk 58, so that when the control disk rotatesin a clockwise direction from the position shown in FIGS. 1 and the lug66 will engage the left edge of the arm 83a of the closing lever andswing the closing lever in a counterclockwise direction on its pivot 82,to the position shown in FIG. 2. During this counterclockwise swingingof the closing lever, the second arm 89b thereof engages the pin 73 onthe blade ring 12 and swings the blade ring 12 in a clockwise direction,thus causing the blades 14 themselves to turn in a clockwise direction,from the fully open position shown in FIGS. 1 and 4, to the closedposition shown in FIG. 2. Although only one blade is shown, it will beunderstood that the ends of the several different blades overlap eachother in the conventional manner so that, when the respective blades arein the positions indicated in FIG. 2, the exposure aperture it) iscompletely closed by the overlapped blades.

During this clockwise movement of the blade ring 12, the exposuredriving pin 31 on the blade ring slides along the inner edge of thecoupling member 23 (which is meanwhi e held against the pin by thespring 34) until the pin reaches a position opposite the driving notchor claw 3% of the coupling member 28, at which time the spring 34 movesthe coupling member 28 into embracing relation to the pin 31,establishing a positive driving connection between the blade ring andthe master member mechanism, as shown in FIG. 2. When the control disk53 moves a little further in a clockwise direction from the positionshown in FIG. 2, the lug 66 on the control disk engages the beveled end52a of the latching lever 52 and shifts the latching lever 52 to releasethe latch which holds the master member mechanism against its runningdown movement.

In order that the opening and closing movements of the blades, forviewfinding and focusing purposes, may be possible, under the influenceof the opening lever 74 and closing lever Si an uncoupling lever isprovided for preventing the engagement of the coupling member 28 withthe pin 31 except when such engagement is desired. This uncoupling leveris illustrated at 86, and it is rotatably mounted on a bolt or screw 83which is conveniently a screw passing through one of the lugs 6 on thefront lens tube 8 to hold this lens tube on the base plate Theuncoupling lever 36 has a restoring spring 92 which bears at one endagainst the periphery of the lens tube 8 and bears at the other endagainst the lever 86 to urge the uncoupling lever in a counterclockwisedirection. At the right hand end of the lever 86 is a downwardly bentflange or lug arranged to cooperate with the upstanding ear or lug 32 onthe coupling lever 28. The other end or left hand end of the uncouplinglever 36 has an arcuate portion 9!!) arranged to cooperate with theupstanding pin as on the control disk 53.

In the initial position ofthe control disk, the pin 68 thereon engagesthe arcuate portion 90 of the uncoupling lever and holds the uncouplinglever in the uncoupling position shown in FIG. 1, which is the sameposition of these parts shown also in FIG. 4. In this position, thearcuate part 96 is concentric with the shaft 65 During the clockwiserunning-down movement of the control disk 58, the pin 68 leaves thearcuate portion 90 just after passing the position shown in FIG. 2 andbefore the latch 52 is released to start the actual exposure motion, sothat the uncoupling lever 85 does not affect the coupling member 28during the exposure. But during the counterclockwise return or restoringmovement ofthe disk 58, the pin dd'engages the part 96? of theuncoupling lever as and moves it to uncoupling position early in thereturn movement before the opening lever 74 begins to act on the pin'73,, and holds it in uncoupling position during the entire remainder ofthe return movement, all the way back to the initial position of thecontrol disk 5'8, which is shown in both FIGS. 1 and 4. This motion ofthe uncoupling lever 86, during the return movement of the disk 58,causes the flange or lug 94 on the uncoupling lever to engage the ear 3yon the coupling member 28 and to move it radially outwardly from itscoupling position, releasing the claw or notch 30 from the pin 31 touncouple the master'member mechanism completely from the blade ring 12so that there will be no interference with moving the blade ring byaction of the opening lever 74, to open the blades for viewing after theconclusion of the exposure.

In order to hold the control disk 58 fast in the position shown in FIG.3, during the actual exposure, there is a latching pawl 96 rotatablymounted on a fixed pivot 98 and urged in a counterclockwise direction bya restoring spring 100. The latching nose of this pawl engages behindthe lug 66 of the disk 58 when the disk has swung all the way around toits extreme position in a clockwise direction, as shown in FIG. 3.However, this latching pawl has a tail 102 which lies in the path ofmovement ofthe pin 78 on the blade ring 12 just as the blade ringcompletes its coimterclockwise movement after making an exposure, sothat just as the exposure is, completed the latching pawl 96 isdeflected by engagement with the pin 72 thereby releasing the lug 66 onthe control disk 58 and allowing the control disk to return in acounterclockwise direction to its initial position. i

The driving and return mechanism for the control shaft fill, togetherwith the mechanism for tensioning or cocking the shutter, will now bedescribed with reference particularly to FIGS. 6 and 7 of the drawings.The description is given with reference to the preferred internalarrangement of a single lens reflex camera, this being advantageousforillustrative reasons, but it does not exclude the possibility thatthe driving and return mechanism and the mechanism for tensioning theshutter may be accommodated in the shutter housing itself. In connectionwith the description of the parts shown in FIGS.

'6 and 7, it should be borne in mind that FIGS. 14 view the parts fromthe front, while FIG. 6 views the parts from the rear, so that anyrotary movement which is described as a clockwise movement in connectionwith FIGS. 1-4 will be a counterclockwise movement of the correspondingpart with reference to FIG. 6, and vice versa. I I

I A shaft 104 in FIGS. 6 and 7 corresponds functionally to the shaft 60of the control disk 58, and maybe either a rearward extension of thesame shaft on or another shaft suitably coupled to the shaft 60 to turntherewith. This shaft 104 is rotatably supported in part in a partition106 of the camera body which is indicated in general at 108. The shaftcarries a gear wheel 110 which meshes with a rack 112 mounted in thecamera body in any convenient conventional way so as to belongitudinally slideable therein. The restoring spring 64, connected tothe left end of the rack 12.2 and pulling leftwardly thereon, urges therack in a leftward direction toward its limit position or rest positiondetermined by a stationary pin 113. Because of the meshing engagementwith the gear 11h, leftward movement of the rack it?) under theinfluence of the spring 64 will turn the shaft 1M in a clockwisedirection when viewed from the rear as in FIG. 6, thereby turning theshaft 60 of the control disk 58 in a counterclockwise direction whenviewed as in FIGS. 1-4.

At the right hand end of the rack 112 is a pawl 114 pivoted to the rackand urged by its restoring spring 113 in a counterclockwise directionaround its pivot, to a limit position determined by engagement of thetail 116 on the pawl with ashoulder on the rack. For cooperation withthe pawl 114, there is a driver pin are projecting from the face of adriver disk 122, which disk carries two stops or abutments 12d and i2 5constructed as bent lugs projecting from the'face of the disk atdifferent radial distances from the center thereof. The disk, togetherwith I a bevel gear 128 connected thereto to turn therewith, is mountedfor rotation on a pivot 13% fixed in the camera. The driving spring 62,already briefly mentioned above, is wound aroundthe pin 1%, and has oneend fixed in any suitable way, such as by hearing against a suitablefixed part, while the other end of this spring bears on the pin 124' andconstantly tends to turn the driver disk 3.22 and the bevel gear 128 ina clockwise direction when viewed as in FIG. 6.

The bevel gear 123 is connected in driving relationship,

through another bevel gear 129 meshing therewith and through anysuitable conventional connections such as those illustratedschematically by the shaft 12% and gears 12% and 131a and shaft 13122,to the shutter tensioning lever 132 mounted in an accessible position onthe camera body, such as on the top wall thereof. In conventional knownmanner, the details of which are not important for purposes of thepresent invention, the lever 132 may serve as a film transport lever aswell as a shutter tensioning or cocking lever, and the connectiondiagrammatically illustrated between the lever M2 and bevel gear 128preferably includes the conventional freewheeling device so that afterthe bevel" gear 128 and the driver disk 122 have been moved to tensionedor cocked position, they may later move back or run down to restposition without 134 underlies the lower end of a release rod 142 whichextends up through the top wall of the camera to an accessible releaseknob or button 144 on the top.

The above mentioned tensioning shaft 4 6 which serves for tensioning orcocking the master member mechanism, has at its rear end a finger M6fixed non-rotatably to the shaft and arranged to be engaged and drivenby a driver pin 147 on a gear wheel 148 which is freely rotatable on asuitable fixed pin or shaft. The gear wheel 143 meshes with a secondgear wheel 15b likewise freely rotatable on any suitable shaft or pin,which gear wheel 150 meshes also with a rack 152 mounted in any suitableknown manner for longitudinal movement and subject to the action of arestoring spring 154 which constantly tends to move the rack 152 in arightward direction when viewed as in FIG.

s,122,os1

6, thus constantly tending to hold the vertical right hand edge of therack against the driver pin 124]) on the disk 3.22.

A conventional drive of a conventional li ht trap flap 156 and reflexviewing mirror 15% is operatively connected in known manner to the gearwheel 11% on the shaft 1%, these connections being illustrated onlyschematically since they are of conventional form and the details arenot important for purposes of the present invention. Suitable diaphragmopening mechanism of known form is preferably also coupled to thecontrol shaft on, bsin operated for example by the gear wheel (FIG. 5)so as to open the adjustable diaphragm to maximum extent for viewfindingand focusing, and then to close it down again to the selected diaphragmaperture at the time the exposure is made, but the details of suchconstruction are known per se and are not important for purposes of thepresent invention.

The construction of the individual parts of the mechanism having nowbeen described, their functional rela tionship and operation will beexplained. Let it be assumed that the shutter parts are in the tensionedor cocked position illustrated in FIGS. 1, 6, and 7. In this positionthe film is protected against undesired exposure by means of the lighttrap flap 156, the viewing mirror 158 is in viewing position, and theshutter blades are wide open, so that an image of the scene is reflectedby the mirror 15% into the conventional viewfinder, not shown, so thatthe operator may compose the scene and focus the camera.

When the photographer is satisfied with the composition and focus, hepresses downwardly on the release plunger 14 This moves the right handend or the latching pawl 134 downwardly so that it no longer is in theway of the abutment 126 on the driver disk E22. Hence the driver diskstarts to turn in a clockwise direction under the influence of itspreviously tensioned spring 62.

As the disk 122 turns, the pin 1% thereon moves arcuately to the rightfrom the position shown in FIG. 6. The pin, acting on the pawl pulls therack 112 rightwardly with it (against the force of its spring at andalso allows the other rack 5.52 to move to the right under the influenceof its spring 154-. The rightward movement of the rack 152 does not moveany parts of the shutter at this time, as it simply withdraws the pin147 away from the finger M6 on the shaft 46, allowing space for theshaft 46 to turn at the proper time during a later stage of the exposure cycle. The rightward movement of the first rack 1.12, does,however, perform important functions.

First, the rightward movement of the rack 112 causes counterclockwiserotation of the gear lid and shaft 164, with consequent clockwiserotation (when viewed as in FIGS. 1-4) of the shaft so and control disk53. The lug or car do on the control disk, engaging the arm 89a of theclosing lever 36, causes the arm 3% of the closing lever to engage thepin 78 on the blade ring 12, to move the blade ring in a clockwisedirection from the position shown in FiG. 1 to the position shown inFIG. 2, thereby swinging the shutter blades id to their extremeclockwise position, completely closing the exposure aperture 1 As theblade ring 112 moves clockwise position, the pin 31 thereon slides alongthe edge of the coupling member until it comes opposite to the notch311i, and the spring then swings the coupling member to cause the notch326 to engage or embrace the pin 31, thereby coupling the blade ring tothe master member mechanism as the blades reach their fully closedposition from the previous open viewing position.

As the shaft il and control disk S8 continue to rotate in a clockwisedirection beyond the position shown in FIG. 2, the lug 66 on the controldisk continues to act on the arm Et a of the lever Sit, therebymaintaining the shutter blades in closed position. During this time, theconnection between the gear lit} and the light trap flap d and mirror15% is effective to move the mirror and the light trap out of the way,to picture-taking position.

Upon further clockwise rotation, the pin ss passes beyond the arcuatepart 9t? of the uncoupling lever $6, permitting the spring $2 to swingthis lever to its ineffective position illustrated in FIG. 3. Then asthe clockwise rotation of the control disk 58 continues further, the lug*5 passes beyond the end of the arm e'ltla and the restoring spring 84restores the closing lever Sti to its normal rest position shown in BIG.1, but the shutter blades still remain closed because the claw or notch3% on the coupling member 28 has meanwhile grasped the pin 31 on theblade ring, thereby holding the blade ring stationary for the timebeing, and preventing the blade ring from moving in a counterclockwisedirection under the influence of its light restoring spring 13.

As the clockwise rotation of the control disk 58 continues, the lug orcar 66 engages the beveled end 52a of the latch lever 52, and swingsthis lever in a counterclockwise direction on its pivot 54, releasingthe nose of the latch from the lug or arm 48 of the mast r membermechanism. Approximately at the end of the clockwise movement of thecontrol disk 58, the nose 5 the lat h snaps over the lug 66 on thecontrol disk 58, as illustrated in FIG. 3, thus holding the control diskagainst return movement in a counterclockwise direction. The releasingof the exposure latch 52 and the engagement of the latch 96 occurapproximately simultaneously with each other, and also approximatelysimultaneously with the release of the rack 112. from the pin whichrelease occurs after approximately one-half of a revolution of thedriver disk 122 (under the influence or" its spring 62) from theposition shown in FIG. 6, and just before the driver disk reaches thelimit of its running down motion, which is limited by engagement of thesecond lug 124 on the driver disk with the end of the latch member v134.During the clockwise motion of the control disk 5 the spring '76 hasbeen able to turn the opening lever '74 in a clockwise direction to anout-of-the-way position (see FIGS. 2 and 3) where it will not interferewith the intended motion of the pin 73 during the subsequent exposure.

:The pin 12% having released the pawl 114 of the rack 112, as abovedescribed, the rack 112 would now be free to move back in a leftwarddirection under the influence of its spring 64, so far as its connectionto the driver disk 122 is concerned. However, it cannot immediately moveback in this direction because it is operatively connected as aboveexplained to the control disk 58 and control shaft 60, which are at thistime latched by the latch 96 as above explained.

When the latch 52 is released by the motion of the lug 66 near the endof the clockwise rotation of the control disk 58, as above explained,the actual exposure part of the exposure cycle begins. The release ofthe latch :52 from the part 48 of the master member mechanism allows themaster member mechanism to run down from its tensioned position seen inFIG. 1 to its rest position shown in FIG. 4, under the influence of themain spring or master spring 36. The running down movement continuesuntil stopped by engagement of an edge of the member 22 with thestationary pin 38. During this running down movement, the master member22 turns in a clockwise direction on its pivot 24 and the associatedmember turns in a counterclockwise direction on its pivot 4s, sincethese members 22 and 4 8 are geared to each other to turn together (butin opposite directions) by the gears 42 and 44'.

The clockwise rotation of the master member 22 pulls the coupling memberin a rightward direction from the position shown in FIG. 3 (whichillustrates the parts just as the latch 52 has been released and themaster member mechanism is beginning its movement) to the posit-ionshown in FIG. 4. Since at this time the pin 31 on the blade ring isembraced by the notch or claw 3th on the coupling member 28, the bladering will be pulled along with the coupling member, rotating in acounterclockwise direction, and will move the shutter blades 14 from theclosed position shown in FIGS. 2 and 3, through a fully open position atthe mid-point of the travel of the blades, and then will closethem againby continued motion in the same direction, the other lobe or wing ofeach blade then lying across the exposure aperture iii in overlappingrelation to the corresponding lobes of the other shutter blades. Thissecond closed position of the double-ended blades is not specificallyshown in the drawings, but will be readily understood by those skilledin the art, especially those familiar with double-ended shutter blades.During the movement of the blade ring in a counterclockwise direction toopen and then close the shutter blades, the blade ring may be acted uponin the usual conventional manner by a conventional clockwork or otherform of delaying or timing mechanism, in order to produce an exposure ofthe desired duration or speed, but this is not illustrated because it isconventional and forms no part of the present invention.

Just as the blade ring 12 completes its counterclockwise rotation andcompletes the closing of the shutter blades after the exposure, the pin'78 on the blade ring engages the tail 102 of the latch 96 and swingsthis latch in a clockwise direction on its pivot 93 (against the forceof its spring 100) so that the latch releases the lug us on the controldisk 58. Thus the control disk is released for its return movement in acounterclockwise direction, under the influence of the restoring spring64 (FIG. 6), it being remembered that at this time the pin 120 hasalready moved beyond the'pawl 114 on the rack 112 so that the rack isfree to return, by the force of the spring :64, as soon as the latch 96is released.

Early in the return movement of the rack 112 and con trol disk 58, theconnections to the light trap flap 156 and reflex mirror 153 areoperated to bring the flap down to its protecting position and to bringthe mirror into viewing position. This protection of the film hasalready been fully accomplished before the control disk as, during itsreturn movement, moves the opening lever 74 to engage the driver pin 7Son the blade ring l2, so as to move the blade ring approximately halfway back from its extreme counterclockwise position toward its extremeclockwise position, thereby putting the shutter blades 14 in theirintermediate position, fully open for viewing the scene and focusing.Also, during this counterclockwise restoring movement of the controldisk 53, and before the opening lever '74 begins to act on the pin '78,the pin as on the control disk engages the arcuate part 9t) of theuncoupling lever as and moves the uncoupling lever to the position shownin 4, so that the flange 9 on the uncoupling lever engages the car 32 onthe coupling member 28 and swings this coupling member on its pivot as,against the force of the spring 34, to disengage the coupling memberfrom the pin 31 on the blade ring. This frees the blade ring completelyfrom the master member mechanism so that the action of the opening lever74 on the pin '78 can turn the blade ring to open the shutter blades,notwithstanding that the master member mechanism remains stationary.

In this way, the parts are restored to the positions shown in 4, inwhich position the exposure has been completed, the film has beenprotected by the flap 356 against further exposure, the master membermechanism (parts 22, 23, 52, 44, and 43, etc.) remain in their run downor rest positions, but the control disk 58 and associated parts havebeen restored. to their initial position by the force of the restoringspring at.

Or" course, all of these movements take place much more quickly thanthetime required to describe them. Although several movements of dilferentparts take place between the time that the release plunger 144 is depressed and the time that the actual exposure begins, all of thesemovements occur in a small fraction of a a second. Likewise after thecompletion of the actual exposure, the restoring movement of the controldisk and the opening of the shutter blades again for viewing, all occurin a small fraction of a second.

At any convenient time after completing the exposure,

the operator may tension or cock the shutter ready for the nextexposure; This is done by operating the lever 132 as above explained,which serves to turn the bevel gear L28 and driver disk 122 back in acounterclockwise direction from their run-down positions to thetensinned or cocked positions shown in FIG. 6. During this tensioningmovement, which involves a rotation of about one-half a revolution, thepin 120- dellects and snaps past the pivoted pawl 114 on the rack 112,without aflecting the position of the rack 1 12, which is meanwhile heldin its leftward position by the force of the spring ti l. "Therefore,the tensioning of the shutter does not in any way atiect the position ofthe protecting flap 156 or the mirror 158, which remain in viewing posi-.tion both before and after the tensioning operation.

148 in a coun erclockwise directiornso that the pin 14"! thereon engagesthe arm 146 on the shaft 46 and turns this shaft in a clockwisedirection when viewed as in lGS. 1-4 (but in a counterclockwisedirection when viewed as in FIG. 6) until the arm 43 latches behind thenose of the main exposure latch 52, thereby holding the master membermechanism in cocked or ten, sioned position until the latch 52 is oncemore released during the next exposure cycle. During this clockwiserotation of the member 48, it momentarily deflects the late- 52, againstthe force of its spring 56, so that the latch snaps behind the arm 48when the latter reaches its fully tensioned position.

The clockwise tensioning movement of the member 43 and shaft 46 istransformed by the gears 42 and 5 into a corresponding counterclockwiserotation of the master.

member 22, thereby winding up and again tensioning the main spring 36.The counterclockwise movement of the crank pin as on the master memberserves to move the coupling member 23 in a leftward direction from therundown position of FIG. 4 to the tensioned position of FIG. 1. luringthis movement the ear 32 on the coupling member 23 rides on the outerface of the flange 94 on the uncoupling lever so until it passes beyondthe pin 3i and drops oil the left end ofthe flange 94-, therebypreventing the notch or claw 30 from engaging the pin 31 when it movespast this pin. It will be remembered that at this time the blade ring 12and pin 31 are in an intermediate position approximately midway of theirtwo extreme positions, with the shutter blades fully open. Afterthe ear32 drops oil the left end of the flange 94, the spring 34 swings thecoupling member 28 clockwise on its pivot 25 until the inner edge of thecoupling member engages the pin 31, the inner edge thereafter slidingpast the pin in contact therewith until the tensioned position of FIG. 1is reached. If desired, there might bea slight depression in the edge ofthe coupling member 28 to engage with the pin 31 when the parts are inthe position shown in FlG. 1, this depression being best seen in MG. 2.p i

it may be mentioned that during the counterclockwise restoring movementof the control disk 58, the lug 6o thereon may touch the arms and Siloof the closing lever 8%, but this does not interfere with the restoringmovement since the spring 84 allows the closing lever 36 to be deflectedslightly in either direction, to the l l extent necessary to enable thelug as to pass the ever 80 during the restoring movement to initialposition.

It may be emphasized at this point that the parts which move during theactual exposure portion of the cycle are few in number and have low massand inertia, so that an exposure of very high speed is possible. Thecontrol disk 58 and associated parts are operatively disconnected fromthe blade ring 12 at the time of the actual exposure, so do not add anymass or inertia or any friction to the parts which must be moved duringthe actual making of the exposure. in the control mechanism as a whole,even including the parts illustrated in FlGS. 6 and 7, there is arelatively small number of components in comparison to the variousfunctions to be performed, and highly satisfactory operation is assured. The parts which serve to open and close the shutter blades duringthe viewing movements (before and after the actual exposure opening)likewise have low mass and inertia and low friction, so that thesemovements can be easily performed with relatively light spring power.

To recapitulate the operation very briefly, downward movement of therelease plunger 144 releases the latch 13 i and allows the driver disk122 to start its clockwise rotation through its range of approximatelyone-half of a. revolution, until it is stopped by engagement of the lug124 with the latch 1314. During this half revolution of the disk 122,the pin 12% thereon draws the rack 112 rightwardly, with the result thatthe control disk turns clockwise the previously open (for viewing)shutter blades are closed by the closing lever 89, and then the lighttrap 156 and mirror 158 are moved to their ineffective positions.

Continued rotation of the control disk 58 releases the second latch 52so that the master member mechanism starts to run down under the powerof its spring 56, the driver disk 122 meanwhile remaining stationary inits rest position. During the running down of the master membermechanism, the master member 22 turns clockwise from the position shownin FIG. 3 to the position shown in FIG. 4, and the coupling member 23,being coupled at this time to the pin 31 on the blade ring 112, drawsthe blade ring with it in a counterclockwise direction, moving theshutter blades from the fully closed position shown in FIG. 3 to swingthe double-ended blades through their completely open position (FIG. 4)to mother fully closed position (not illustrated) where the oppositelobes of the blades serve to close the aperture 10. At the conclusion ofthis exposure operation, the pin 78 on the blade ring unlatches thethird latch 96 so that the control disk 58 can return in acounterclockwise direction under the influence of the spring 64, andduring this return movement the light trap 156 is restored to itsprotecting position with respect to the film 162, after which theopening lever 74 is operated by the movement of the control disk 58 toengage the pin '7 8 to move the shutter blades once more to the openviewing position shown in FIG. 4. Thus the shutter blades are normallyopen, for viewing and focusing purposes, both before and after theactual exposure, and they remain open while the master member mechanismis being restored from its run-down or re" position of FIG. 4 to itstensioned position of FIG. 1.

It is seen from the foregoing disclosure that the above mentionedobjects of the invention are well fulfilled. It is to be understood thatthe foregoing disclosure is given by way of illustrative example only,rather than by way of limitation, and that without departing from theinvention, the details may be varied within the scope of the appendedclaims.

What is claimed is:

1. An objective photographic shutter for a single lens reflex camera,comprising double ended shutter blades each mounted for pivotal movementin a single direction from a first closed position at one end of itsrange of travel through an intermediate open position to a second closedposition at the opposite end of its range of travel,

a rotatable blade ring operatively connected to said blades to move themin one direction through said range by movement of said blade ring inone direction through its range of travel, a spring operated drivingelement, and a main spring for driving the same, characterized by theprovision of a positive driving connection between said driving elementand said blade ring during movement of said blade ring in one directionto make an exposure by moving said blades from their first closedposition through open position to their second closed position, a rotarycontrol member, an uncoupling lever oscillatable on a fixed axis, aportion of said rotary control member being arranged, during rotation ofsaid control member in one direction, to operate said uncoupling leverto disconnect said positive driving connection after the shutter bladesreach their second closed position, a blade opening lever alsooscillatable on a fixed axis, a portion of said rotary control mem erbeing arranged, during rotation in said one direction, to operate saidopening lever to cause said opening lever to engage and move said bladering to an intermediate blade-open position subsequent to thedisconnection of said driving connection, a blade closing leveroscillatable on a fixed axis, and a portion of said rotary controlmember being arranged, during rotation of said control member in anopposite direction, to operate said closing lever to cause said closinglever to engage and move said blade ring in the same direction in whichit was moved by said opening lever, to one end of its range of travel toclose the shutter blades.

2. A construction as defined in claim 1, further including a returnspring operatively connected to said rotary control member to tend toturn it in said one direction, and a drive spring operatively connectedto said rotary control member to turn it in said opposite direction withsufiicient force to overcome the force of said return spring and totension the return spring, the operative connection between said drivespring and said control member being automatically disconnected at theend of rotation of said control member in said opposite direction sothat said return spring may then turn said control member in said onedirection.

3. A construction as defined in claim 2, further including a latch forholding said rotary control member substantially at the end of itsmovement in said opposite direction, to retain it against returnmovement in said one direction under the force of said return spring,and a part on said blade ring for engaging said latch to unlatch itsubstantially at the end of movement of said blade ring inexposure-making direction, so that said return spring may then turn saidrotary control member in its said one direction to disconnect thedriving connection between the driving element and the blade ring and tomove the blade ring to an intermediate position to open the blades.

4. An objective photographic shutter for a single lens reflex camera,comprising double ended shutter blades each mounted for pivotal movementin a single direction from a first closed position at one end of itsrange of travel through an intermediate open position to a second closedposition at the opposite end of its range of travel, a rotatable bladering operatively connected to said blades to move them in one directionthrough said range by movement of said blade ring in one directionthrough its range of travel, a spring operated driving element, and amain spring for driving the same, characterized by the provision of apositive driving connection between said driving element and said bladering during movement of said blade ring in one direction to make anexposure by moving said blades from their first closed position throughopen position to their second closed position, a rotary control membereffective during rotation in one direction to disconnect said positivedriving connection between said driving element and said blade ring andto move said blade ring to an intermediate blade-open position andeffective during rotation in an opposite direction to move said bladering a further distance in the same direction to close the blades,

a drive spring for driving said rotary control member in said oppositedirection, means for freeing said control member from said drive springat the end of the movement of said control memberin said oppositedirection, a return spring for turning said control member in said onedirection when it is freed from said drive spring, and means forconcomitantly tensioning said main spring of said driving element,tensioning said drive spring, and reconnecting said drive springoperatively to said rotary control member.

5. A construction as defined in claim 4, further including a firstreleasable latch for holding said drive spring in tensioned position, asecond releasable latch for holding said main spring in tensionedposition, a third releasable latch for holding said rotary controlmember substantially at the end of its movement in said oppositedirection to prevent return thereof in said one direction under theforce of said return spring, said rotary control memher being normallyin a rest position at the end of its movement in said one direction whenthe shutter has been tensioned and is ready for operation through a newexposure cycle, means for releasing said first latch to initiate anexposure cycle so thatsaid drive spring may drive said control member insaid opposite direction, means operated by movement of said controlmember in said opposite direction for releasing said second latch sothat said main spring may operate said driving element to move saidblade ring to open and then to close the shutter blades, and meansoperated by movement of's aid blade ring for releasing said third latchso that said return spring may move said control member in its said onedirection back to its rest position.

6. A photographic shutter comprising blades movable through a range froma first extreme position through an intermediate position to a secondextreme position, said blades being open to admit light in saidintermediae position and being closed to exclude light in both of saidextreme positions, a master spring, a master driving member operativelyconnected to said master spring to be driven thereby through arunning-down movement from a tensioned position to a rest position, acontrol member movable through a range of movement between a tensionedposition and a rest position, arestoring spring operatively connected tosaid control member to move it from tensioned position to rest'position,a drive element movable through a range of movement between a tensionedposition and a rest position, a drive spring operatively connected tosaid drive element to move it from tensioned position to rest position,means for moving said drive element from rest position to tensionedposition, means operated by movement of said drive element from restposition to tensioned position for moving said master driving memberfrom its rest position to tensioned position, a first releasable late,for holding said drive element in tensioned position, a secondreleasable latch for holding said master driving member in its tensionedposition, a third releasable latch for holding said control member inits tensioned position, a movable coupling element shiftable between anuncoupled position and a couplin position effective to couple saidmaster driving member in operative driving relation to said blades,means for releasing said first latch to initiate an exposure cycle whensaid blades are in said intermediate position, so that said driveelement may move from its tensioned position toward its rest position,means operated by such movement of said drive elemen for moving saidcontrol member fromits rest position to its tensioned position, meansoperated by such movement of said control member for moving said bladesfrom intermediate position to their first extreme position, means formoving said coupling element to coupling position while said masterdriving member is in tensioned position and said blades are in theirfirst extreme position, means also operated by movement of said controlmember toward tensioned position for releasing said second latch so thatsaid master driving member may move from its tensioned position to itsrest position, means operated by such movement oisaid master drivingmember and acting through said coupling element for moving said bladesfrom their first extreme position through intermediate position to theirsecond extreme position, means operated by said blade moving means forreleasing said third latch substantially when said blades reach theirsecond extreme position so that said control member may move from itstensioned position toward its rest position, and means operatedby suchmovement of said control member for shifting said coupling element touncoupled position and for moving said blades from their second extremeposition to their intermediate position.

References Cited in the file of this patent UNITED STATES PATENTSFaulhaber Jan; 10, 1956

1. AN OBJECTIVE PHOTOGRAPHIC SHUTTER FOR A SINGLE LENS REFLEX CAMERA,COMPRISING DOUBLE ENDED SHUTTER BLADES EACH MOUNTED FOR PIVOTAL MOVEMENTIN A SINGLE DIRECTION FROM A FIRST CLOSED POSITION AT ONE END OF ITSRANGE OF TRAVEL THROUGH AN INTERMEDIATE OPEN POSITION TO A SECOND CLOSEDPOSITION AT THE OPPOSITE END OF ITS RANGE OF TRAVEL, A ROTATABLE BLADERING OPERATIVELY CONNECTED TO SAID BLADES TO MOVE THEM IN ONE DIRECTIONTHROUGH SAID RANGE BY MOVEMENT OF SAID BLADE RING IN ONE DIRECTIONTHROUGH ITS RANGE OF TRAVEL, A SPRING OPERATED DRIVING ELEMENT, AND AMAIN SPRING FOR DRIVING THE SAME, CHARACTERIZED BY THE PROVISION OF APOSITIVE DRIVING CONNECTION BETWEEN SAID DRIVING ELEMENT AND SAID BLADERING DURING MOVEMENT OF SAID BLADE RING IN ONE DIRECTION TO MAKE ANEXPOSURE BY MOVING SAID BLADES FROM THEIR FIRST CLOSED POSITION THROUGHOPEN POSITION TO THEIR SECOND CLOSED POSITION, A ROTARY CONTROL MEMBER,AN UNCOUPLING LEVER OSCILLATABLE ON A FIXED AXIS, A PORTION OF SAIDROTARY CONTROL MEMBER BEING ARRANGED, DURING ROTATION OF SAID CONTROLMEMBER IN ONE DIRECTION, TO OPERATE SAID UNCOUPLING LEVER TO DISCONNECTSAID POSITIVE DRIVING CONNECTION AFTER THE SHUTTER BLADES REACH THEIRSECOND CLOSED POSITION, A BLADE OPENING LEVER ALSO OSCILLATABLE ON AFIXED AXIS, A PORTION OF SAID ROTARY CONTROL MEMBER BEING ARRANGED,DURING ROTATION IN SAID ONE DIRECTION, TO OPERATE SAID OPENING LEVER TOCAUSE SAID OPENING LEVER TO ENGAGE AND MOVE SAID BLADE RING TO ANINTERMEDIATE BLADE-OPEN POSITION SUBSEQUENT TO THE DISCONNECTION OF SAIDDRIVING CONNECTION, A BLADE CLOSING LEVER OSCILLATABLE ON A FIXED AXIS,AND A PORTION OF SAID ROTARY CONTROL MEMBER BEING ARRANGED, DURINGROTATION OF SAID CONTROL MEMBER IN AN OPPOSITE DIRECTION, TO OPERATESAID CLOSING LEVER TO CAUSE SAID CLOSING LEVER TO ENGAGE AND MOVE SAIDBLADE RING IN THE SAME DIRECTION IN WHICH IT WAS MOVED BY SAID OPENINGLEVER, TO ONE END OF ITS RANGE OF TRAVEL TO CLOSE THE SHUTTER BLADES.